1. Field of the Invention
The present invention relates to hinges and more particularly, to a hinge, which is capable of absorbing stress, avoiding component damage due to stress concentration.
2. Description of the Related Art
Hinges are intensively used in many objects in our daily life. For examples, hinges are commonly used in notebook computers, electronic dictionaries, PDAs and many other electronic devices to connect two solid members, for example, the base member and the cover member, allowing only a limited angle of rotation between them.
A conventional hinge 9, as shown in FIGS. 4 and 5, comprises a knuckle 91 and a pivot shaft 92. The knuckle 91 comprises a flat base portion 911, an upright bearing portion 912 extended from one side of the flat base portion 911, and a constraint portion 913 circularly curved and extended from the end of the upright bearing portion 912 opposite to the flat base portion 911. The pivot shaft 92 is rotatably inserted through the knuckle 91, defining a flat positioning face 921. When rotating the pivot shaft 92 to the angle where the flat positioning face 921 is abutted against the flat base portion 911, as shown in FIG. 5, the pivot shaft 92 is firmly kept in position subject to the pressure of the constraint portion 913. When rotating the pivot shaft 92 to move the flat positioning face 921 away from the flat base portion 911, the pivot shaft 92 imparts a pressure to the constraint portion 913 in direction away from the flat base portion 911. At this time, a stress is produced and concentrated on the connection area between the upright bearing portion 912 and the constraint portion 913. However, as the connection area between the upright bearing portion 912 and the constraint portion 913 is stopped against the periphery of the pivot shaft 92, it is not movable to absorb or release the stress and may break easily after a long use.